text: /* s_scalbnf.c -- float version of s_scalbn.c.
   * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
   */
  
  /*
   * ====================================================
   * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   *
   * Developed at SunPro, a Sun Microsystems, Inc. business.
   * Permission to use, copy, modify, and distribute this
   * software is freely granted, provided that this notice
   * is preserved.
   * ====================================================
   */
  
  #include <sys/cdefs.h>
  #if defined(LIBM_SCCS) && !defined(lint)
  __RCSID("$NetBSD: s_scalbnf.c,v 1.9 2010/04/23 19:17:07 drochner Exp $");
  #endif
  
  #include "namespace.h"
  #include "math.h"
  #include "math_private.h"
  
  #ifdef __weak_alias
  __weak_alias(scalbnf, _scalbnf)
  #endif
  
  static const float
  two25   =  3.355443200e+07,	/* 0x4c000000 */
  twom25  =  2.9802322388e-08,	/* 0x33000000 */
  huge   = 1.0e+30,
  tiny   = 1.0e-30;
  
  float
  scalbnf(float x, int n)
  {
  	int32_t k,ix;
  	GET_FLOAT_WORD(ix,x);
          k = (ix&0x7f800000)>>23;		/* extract exponent */
          if (k==0) {				/* 0 or subnormal x */
              if ((ix&0x7fffffff)==0) return x; /* +-0 */
  	    x *= two25;
  	    GET_FLOAT_WORD(ix,x);
  	    k = ((ix&0x7f800000)>>23) - 25;
              if (n< -50000) return tiny*x; 	/*underflow*/
  	    }
          if (k==0xff) return x+x;		/* NaN or Inf */
          k = k+n;
          if (k >  0xfe) return huge*copysignf(huge,x); /* overflow  */
          if (k > 0) 				/* normal result */
  	    {SET_FLOAT_WORD(x,(ix&0x807fffff)|(k<<23)); return x;}
          if (k <= -25) {
              if (n > 50000) 	/* in case integer overflow in n+k */
  		return huge*copysignf(huge,x);	/*overflow*/
  	    else return tiny*copysignf(tiny,x);	/*underflow*/
  	}
          k += 25;				/* subnormal result */
  	SET_FLOAT_WORD(x,(ix&0x807fffff)|(k<<23));
          return x*twom25;
  }
  